Article, method, and apparatus for electrochemical fabrication

ABSTRACT

An electroplating method that includes: a) contacting a first substrate with a first article, which includes a substrate and a conformable mask disposed in a pattern on the substrate; b) electroplating a first metal from a source of metal ion onto the first substrate in a first pattern, the first pattern corresponding to the complement of the conformable mask pattern; and c) removing the first article from the first substrate, is disclosed. Electroplating articles and electroplating apparatus are also disclosed.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional ApplicationNo. 60/043,742 filed on Apr. 4, 1997.

BACKGROUND OF THE INVENTION

[0002] The invention relates to forming structures by electrochemicaldeposition.

[0003] Microfabrication processes (also referred to as micromachining)are being developed and refined for eventual application to themanufacture of complex devices including machines and instrumentation.These processes are being directed to the production of machines ofminiaturized devices having features in the range of a few microns andin some cases submicron, some of which currently exist on a macroscopicscale.

[0004] Microfabrication processes include: bulk micromachining, in whichmaterial is removed from regions of a substrate; surface micromachining,in which a thin conformal structural layer and one or more sacrificiallayers are deposited onto a substrate; and LIGA, which generates 2.5-Dextruded shapes by molding materials around metals electrodepositedwithin openings in thick synchrotron-processed photoresists. Theseprocesses are used to produce structures of simple geometries (e.g.,they can be defined by 1-4 different cross sections), and are usuallycustomized for each application.

[0005] Solid freeform fabrication, which is also referred to as rapidprototyping, is used to manufacture macroscopic parts from hundreds oflayers by generating one layer at a time. These processes producefeatures typically greater than 50-100 um in width using layerstypically greater than 50-150 um thick. These processes typicallygenerate a layer serially. These processes employ structures forsupporting the part being manufactured. The support structures are oftencustomized to the part.

SUMMARY OF THE INVENTION

[0006] In one aspect, the invention features an electroplating methodthat includes: a) contacting a first substrate with a first article,which includes a substrate and a conformable mask disposed in a patternon the substrate; b) electroplating a first metal from a source of metalions onto the first substrate in a first pattern, the first patterncorresponding to the complement of the conformable mask pattern; and c)removing the first article from the first substrate.

[0007] In preferred embodiments, the method further includeselectroplating a second metal from a second metal ion source onto thefirst substrate. In one embodiment, the step of electroplating thesecond metal includes: a) contacting the first substrate with a secondarticle including a substrate and a conformable mask disposed in apattern on the substrate; b) electroplating a second metal onto thefirst substrate in a second pattern, the second pattern corresponding tothe complement of the conformable mask pattern of the second article;and c) removing the second article from the first substrate. The methodcan further include building additional layers.

[0008] In one embodiment, the invention features an electroplatingmethod that includes repeatedly contacting a substrate with a patternedconformable mask; electroplating a first metal form a source of ionsonto the substrate in a pattern, the pattern corresponding to thecomplement of the conformable mask pattern; and removing the mask fromthe substrate.

[0009] In another embodiment, the invention features a method formanufacturing an element that includes forming a multi-layer structureby repeatedly forming layers according to the above-describedelectroplating methods.

[0010] In another aspect, the invention features an electroplatingarticle that includes a substrate having a first major surface and aconformable mask disposed in a pattern on the first major surface of thesubstrate. The article is capable of electroplating a pattern of metalcomplementary to the pattern of the conformable mask onto an electrodewhen the article is placed in contact with the electrode in the presenceof a metal ion source and subjected to an electric field.

[0011] In other aspects, the invention features an electroplatingapparatus that includes an electrolyte, which includes ions of a firstmetal and ions of a second metal, an anode in contact with theelectrolyte, a cathode in contact with the electrolyte, and a firstarticle (e.g., the above described electroplating article) in contactwith the electrolyte.

[0012] In one embodiment, the electroplating apparatus includes a firstelectroplating reservoir that includes an electrolyte, which includes afirst metal ion, disposed within the first reservoir, an anode incontact with the electrolyte, a cathode in contact with the electrolyte,and an article (e.g., an article described above) in contact with theelectrolyte; a second electroplating reservoir that includes anelectrolyte, which includes ions of a second metal, disposed within thesecond reservoir, and an anode in contact with the electrolyte.

[0013] In another aspect, the invention features a method formanufacturing an electroplating article. The method includes: a)applying a conformable mask to an article comprising a first substrateand a patterned resist disposed on the first substrate; b) contacting asecond substrate to said conformable mask such that the conformable maskobtains a pattern complementary to the resist pattern; c) separating thefirst substrate from the conformable mask (the conformable maskremaining adhered to the article); and d) removing the resist.

[0014] In one embodiment, the method for manufacturing an electroplatingarticle includes providing a porous medium having a first surface; b)treating said porous medium to create one or more nonporous regions; c)applying a film to said first surface of said porous medium; d)patterning the film to create a patterned mask; and e) removing at leasta portion of the one or more nonporous regions.

[0015] In other aspects, the present invention is directed to thecalculation, storage and retrieval of cross section geometry of a threedimensional object for generation of patterned masks reflecting thatgeometry and for use in an electroplating method. The data and controlprocesses of the invention can be implemented by a software applicationprogram executed in a general purpose computing system.

[0016] The data and control processes of the invention can be embodiedin an electroplating method implemented via the application program andalso in an article of manufacture, in the form of a data storage medium,that stores application program code arranged to carry out that methodupon execution by a processor.

[0017] The electroplating methods and articles allow fabrication ofdevices from thin layers of materials such as, e.g., metals, polymers,ceramics, and semiconductor materials. The electroplating methodsproduce relatively homogeneous, isotropic elements (e.g., devices)without interlayer junctions. The electroplating methods can beperformed at low temperatures, thus-allowing substrates such asintegrated circuits and silicon wafers to be used as plating substrates.

[0018] The electroplating methods of the invention can be used tofabricate devices of freeform geometry including high aspect ratiodevices, hollow devices with internal features, devices withcantilevered and “chandelier” geometries, and functional assemblies ofinterconnected, stationary or moving parts (i.e., devices fabricated inan assembled state). The electroplating articles, apparatus, and methodsalso are particularly useful in mass production of devices.

[0019] Other features and advantages of the invention will be apparentfrom the following description of the preferred embodiments thereof, andfrom the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020]FIG. 1 is view taken in cross section of an electroplating articleaccording to one embodiment of the invention;

[0021]FIG. 2 is a view taken in cross section of an electroplatingarticle according to a second embodiment of the invention;

[0022]FIG. 3 is a diagram of a first embodiment of a method for formingan electroplating article;

[0023]FIG. 4 is a diagram of a second embodiment of a method for formingan electroplating article;

[0024]FIG. 5 is a diagram of a third embodiment of a method for formingan electroplating article;

[0025]FIG. 6 is a diagram of a fourth embodiment of a method for formingan electroplating article;

[0026]FIG. 7 is a diagram of a fifth embodiment of a method for formingan electroplating article;

[0027]FIG. 8 is a diagram of a sixth embodiment of a method for formingan electroplating article;

[0028]FIG. 9 is a diagram of a seventh embodiment of a method forforming an electroplating article;

[0029]FIG. 10 is a diagram of a method for forming a deposit accordingto an electroplating method of the invention;

[0030]FIG. 11 is a diagram of a method according to a first embodimentof the electroplating method of the invention;

[0031]FIG. 12 is a diagram of a method according to a second embodimentof the electroplating method of the invention;

[0032]FIG. 13 is a diagram of a method for fabricating an element on anintegrated circuit;

[0033]FIG. 14 is a diagram of a method for assembling elementsfabricated together;

[0034]FIG. 15 is a diagram of an element manufactured according to oneembodiment of the electroplating method of the invention;

[0035]FIGS. 16a-d are views taken in cross section of elementsmanufactured according to one embodiment of the invention;

[0036]FIG. 17 is an electroplating apparatus according to one embodimentof the present invention;

[0037]FIG. 18 is a view taken in cross section of a substrate in contactwith an electroplating article;

[0038]FIG. 19 is a top view of a portion of an electroplating apparatusof the invention;

[0039]FIG. 20 is a top view of a portion of an electroplating apparatusaccording to a third embodiment of the electroplating apparatus ofpresent invention;

[0040]FIG. 21 is a top view of a portion of an electroplating apparatusaccording to a fourth embodiment of the electroplating apparatus of thepresent invention;

[0041]FIG. 22 is a view taken in cross section of one embodiment of anelectroplating article holder of the present invention;

[0042]FIG. 23 is a view taken in cross section of a second embodiment ofan electroplating apparatus of the present invention;

[0043]FIG. 24 is a highly enlarged view taken in cross section of asubstrate in position in the electroplating apparatus of FIG. 23;

[0044]FIG. 25 is a view taken in cross section of a third embodiment ofa portion of an electroplating apparatus of the invention;

[0045]FIG. 26 is a view taken in cross section of another portion of theelectroplating apparatus of FIG. 25;

[0046]FIG. 27 is a diagram of a three dimensional object (shown in twodimensions) with cross section lines indicated;

[0047]FIG. 28 is a functional block diagram of a computing systemconfigured for calculation of cross sections of a three dimensionalstructure and for driving an electroplating apparatus of the presentinvention;

[0048]FIG. 29 is a flow diagram illustrating a method for generatingmask pattern files and apparatus control files;

[0049]FIG. 30 is a flow diagram illustrating a method for manufacturinga three dimensional object;

[0050]FIG. 31 is a view taken in cross section of an electromagneticmotor;

[0051]FIG. 32 is a diagram of an electroplating method employing morethan one article according to a third embodiment of the electroplatingarticle of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0052] The invention features electroplating methods, apparatus andarticles that enable the manufacture of elements having complexstructures. The electroplating methods include selective electroplatingof layers that may include both structural materials (e.g., metals) andsupport (i.e., sacrificial) materials; and subsequent removal (e.g., byetching, melting, or electrolytically dissolving) of the supportmaterials. The structural material remaining after removal of thesupport material defines an element such as a microscopic or mesoscopicdevice. The electroplating methods employ electroplating articles thatinclude a patterned conformable mask, optionally adhered to a supportsuch as an electrode or a porous medium.

[0053] In general, the invention features electroplating articles foruse in electroplating methods. The electroplating method occurs in anelectroplating apparatus that includes an electroplating bath filledwith electrolyte, an anode, and a cathode. The electrolyte containsmetal ions and, optionally, other additives. The anode can be part ofthe electroplating article, as described below, or can be located at adistance from the article. Throughout this application, the substrate tobe plated functions as the cathode unless otherwise specified. Tosimplify the description, the materials are referred to as metals andsimilar features are indicated with the same reference numerals.

Electroplating Article

[0054] Referring to FIG. 1, electroplating articles 4, of the inventioninclude a patterned conformable mask 6 adhered to a support 8. Theelectroplating article can also be a patterned conformable mask. Thesupport can be a porous medium (e.g., a filter), an anode, andcombinations thereof. The article can include a plurality of differentmask patterns on a single support. The different mask patterns can becontacted by a substrate in a predetermined sequence to sequentiallyplate a plurality of metal layers where each metal layer has a patterncorresponding to the complement of the mask pattern contacted, to form amulti-layered element. Referring to FIG. 2, electroplating article 4 caninclude one or more edge masks 3 on the outer surface of the article,for confining the metal being plated.

[0055] Contact between the electroplating article and the substrate tobe plated is made by pressing the patterned mask against the substrateusing a well-controlled, uniform pressure. The appropriate maskingpressure will prevent flash (i.e., the deposition of metal in the areacovered by the mask), and will prevent distortion of the featuresdefined by the mask. When the electroplating article is removed fromcontact with the substrate, the mask remains adhered to theelectroplating article.

[0056] A variety of methods can be used to improve release of the maskfrom the substrate to be plated so as to prevent delamination of themask from the support; gradually peeling the electroplating article (ifflexible) off of the substrate with the aid of a dull blade; adding anon-stick/lubricating compound to the electrolyte; coating the masksurface with a non-stick composition (e.g., sputteredpolytetrafluoroethylene); and vibration (e.g., ultrasound).

Patterned Conformable Mask

[0057] The patterned conformable mask is sufficiently deformable (e.g.,elastically deformable) to permit conformance of the mask to the surfaceof a substrate to be plated to maximize contact between the mask and thesubstrate, and to minimize (preferably eliminate) the presence of gapsbetween the mask and the substrate. Maximizing contact between the maskand the substrate minimizes the potential for flash formation. The maskis also sufficiently durable to enable repeated use (i.e., contactingwith and removing from a substrate). The mask is sufficiently rigid andthin to prevent distortion of the mask features (i.e., the positive andnegative features constituting the closed and open features of the maskpattern respectively) by the masking pressure. The mask preferably isrelatively thick compared to its peak and valley roughness and thecurvature of the substrate to be plated.

[0058] The mask preferably exhibits very high volume electricalresistivity (e.g., 10⁻¹⁴ Ohm-cm), has a very low permeability to ions inthe electrolyte solution, and is chemically non-reactive with theplating electrolytes at the temperatures at which the plating operationis conducted. The mask can be hydrophilic or hydrophobic, withhydrophilic being preferred. In the case of hydrophobic materials,relatively higher amounts of wetting agents can be included in theelectrolyte to ensure wetting of the mask material.

[0059] The mask preferably is capable of forming a strong bond (e.g., achemical or mechanical bond) to the support, such that small (e.g.,15×15 μm) isolated positive features are not delaminated by the maskfabrication process, normal handling of the mask or by removal of themask material from the substrate to be plated.

[0060] The patterned mask is preferably substantially planar and smoothto enable conformance to the substrate to be plated. The mask is capableof being patterned with negative and positive features of varyingdimensions (e.g., 10-25 um or smaller, such as submicron), preferablywith no mask residue blocking the negative features of the mask pattern.The pattern of the mask includes apertures (i.e., negative features)extending through the mask thickness and defined by one or more sidewalls of the mask. The mask features preferably have a substantiallyplanar wall profile and may have a slight wall angle (e.g., slightlydivergent toward the substrate to be plated) re-contacting the mask tothe substrate in the presence of an existing deposit.

[0061] The mask can be compound so as to include one or more layers ofmaterial, e.g., a relatively rigid layer (i.e., a high aspect ratiophotoresist, e.g., SU-8 commercially available from MicroChemCorporation and synchrotron-processed polymethylmethacrylate), and aconformable layer. Another example of a useful rigid layer is a positivephotoresist such as Clariant AZ4620, which can be patterned by exposingit to ultraviolet light through the patterned conformable layer.

[0062] Examples of useful masking compositions include elastomers suchas, e.g., polydimethylsiloxane (i.e., silicone rubber) commerciallyavailable, e.g., under the trade designation Sylgard from Dow-Corning(e.g., Sylgard 182 and 184), and under the trade designation RMS-033from Gelest. The masking compositions can include other additives, e.g.,photoinitiators, fillers, and hydrogen getters.

Porous Medium

[0063] The porous medium has interconnected pores and is permeable toions and additives present in electrolyte compositions. The porousmedium can have one or more layers of varying porosity. The porousmedium preferably has a pore size considerably finer than the minimumnegative feature of the mask. The pores are preferably uniform in openarea, e.g., the open area of any 20 μm square of the medium isconsistent to 1%. Particularly useful porous mediums, when used asfilters, have a particle retention rating of 0.3-3 μm. For those porousmediums that include multiple porous layers, each porous layer can varyin porosity and pore size, with the porous medium in closest proximityto the substrate to be plated exhibiting the above characteristics. Thesurfaces of the porous medium that contact the mask should besufficiently flat and smooth to ensure that the surface of the adheredmask that contacts the substrate to be plated is also flat and smooth.

[0064] The porous medium is chemically non-reactive with the electrolytesolution at the operating temperature of the electrolyte bath. Preferredporous mediums are hydrophilic. The porous medium preferably ispermeable to gas to allow venting of gas bubbles generated during theelectroplating method.

[0065] Preferably the porous medium is free from shedding (i.e., doesnot release portions of itself into surrounding fluid), and issufficiently durable so as to withstand multiple electroplatingoperations. Examples of suitable porous medium materials include rigid,hydrophilic, slip cast ceramic disk porous mediums (commerciallyavailable from Coors Ceramics) and hydrophilized membrane porous mediumsmade from, e.g., polypropylene (commercially available under the tradedesignation GH from Gelman), polyvinylidenefluoride (commerciallyavailable under the trade designation Durapore from Millipore) andpolytetrafluoroethylene (commercially available under the tradedesignation LCR from Millipore). Rigid porous mediums can providemasking pressure when supported by their edges alone.

[0066] Particularly useful highly permeable, porous mediums includerelatively thin, flexible, porous membranes. Porous membranes can becombined with a more rigid porous medium, which serves as a backing toprovide the requisite pressure for masking applications. The porousmembrane can be sandwiched between the more rigid porous medium and themask and the porous medium can be used to supply the requisite maskingpressure for the plating operation. The more rigid porous medium canhave a relatively more coarse (i.e., larger) porosity than that usefulfor direct contact with the mask. Porous membranes can be integratedwith the mask composition (or transformed into a mask).

[0067] To assist handling, porous membranes can be installed in thedrumhead fixture described below, or temporarily adhered to a rigid flatsubstrate (e.g., a silicone wafer, glass) with an adhesive composition(e.g., dry film photoresist). Porous membranes can be processed whileadhered to the substrate and, after processing, removed by dissolvingthe adhesive.

[0068] Masking pressure can be applied to the porous membrane by themomentum of a stream or jet of electrolyte impinging on the membranefrom behind, optionally in combination with dense particles incorporatedinto the electrolyte, and increasing the viscosity of the electrolyte,for example, by the addition of a polymer. Masking pressure can also beapplied to the membrane by sealing the membrane against the walls of thetank of the electroplating system and then pressurizing the electrolyte,causing the membrane to be pushed against the substrate to be plated. Adummy substrate can be used when the substrate to be plated is smallerthan the porous medium to prevent the membrane from bulging.

[0069] One example of an electroplating method that employs a porousmembrane includes pressing a relatively more rigid porous medium againstthe membrane, applying current, depositing a metal for a period,removing the current, withdrawing the rigid porous medium from contactwith the membrane, slightly displacing the relatively more rigid porousmedium in its own plane (e.g., in an orbital or linear fashion), andrepeating the cycle. Displacing the relatively more rigid porous mediumduring each cycle allows a different portion of the rigid porous mediumto make contact with the membrane. Preferably the mask/membraneseparates from the substrate to be plated while the relatively morerigid porous medium is separated from the membrane so as to allowexchange of fluids between the microvolume and bulk electrolyte.

[0070] Another membrane plating method includes pressing a granularmedium, tiny spheres, or rollers against the membrane using, e.g., arigid screen. The tiny spheres and rollers can be rotated in a pattern(e.g., a linear pattern using linear movement or a circular patternusing an orbital movement) on the membrane continuously orintermittently so as to average the local non-uniformities in porestructure of the rollers/spheres. Preferably the amplitude of movementis equal to (more preferably several times greater than) the diameter ofthe sphere or cylinder. Preferably the spheres/cylinders are relativelysmall and the membrane is relatively thick. The spheres/cylinders can bemade of the metal being plated.

Anode

[0071] The electroplating article can consist of a patterned mask on ananode. The anode can be soluble or insoluble, rigid or flexible, porousor nonporous, and can include an erodable layer (e.g., a metal layer)supported by a conductive material that does not erode (e.g., platinizedtitanium). The anode can be of any dimension including a thin flexiblesheet of metal.

[0072] A soluble anode will tend to erode during use. The anode can be“redressed” periodically by reversing the polarity of the anode andplating metal back onto the anode through the negative features of themask. The excess metal is supplied by the electrolyte in conjunctionwith another anode according to, e.g., through-mask plating processesused in electronics manufacturing. For a system in which the mask isphysically supported by and attached to a porous medium, and an anode islocated directly behind the membrane, moving the anode will preventlocalized erosion of the anode.

Forming Electroplating Articles

[0073] In general, methods for forming electroplating articles includeapplying a solid mask or liquid masking composition to a support, i.e.,an anode, a porous medium and combinations thereof. The solid mask canbe patterned prior or subsequent to attachment to the support. Liquidmasking compositions can be patterned on a non-porous substrate (e.g.,inert material, or a material that can be dissolved or melted (e.g.,substrates of plastic, lacquer, or low melting point alloy)), cured(i.e., crosslinked, polymerized, hardened, solidified, gelled, andcombinations thereof), and attached to a support or patterned andsolidified directly on the support.

Preparation of the Support

[0074] It is preferable to planarize the surface of the support thatwill receive the mask, so as to provide a smooth flat surface forreceiving the mask. When applying the mask to an anode, it is preferableto first prepare the anode surface so as to maximize adhesion to themask. Examples of useful anode surface preparation methods includechemical microetching, lapping, sandblasting, and sintering a thin layerof powder onto the surface. A chemical adhesion promoter (e.g., SylgardPrime Coat) can also be used.

[0075] A variety of methods can be used to maintain or improve adhesionof the mask to a porous medium. These methods include melting the maskwhile pressing it into the porous medium resulting in a mechanicalinterlocking of the mask with the porosity of the porous medium, andapplying an adhesive composition between the mask and the porous medium.Adhesion of the mask to the porous medium can also be enhanced byemploying an adhesive that is a meltable material (e.g., glass), whichcan be dry deposited (e.g., sputtered) onto the surface of the patternedmask. When using an adhesive composition, it is preferable to employmethods that confine the adhesive composition to the areas locatedbetween the mask and the support (i.e., preventing the adhesive frombridging a negative feature that is only a few microns wide).

[0076] Liquid masking composition has a tendency to soak into (i.e.,uncontrollably absorb into) the pores of a porous medium. A variety ofmethods can be employed to reduce “soak in” in regions of the porousmedium that are to remain porous. Examples of suitable methods forpreventing soak in include: supplying pressurized air to one side of theporous medium; treating the porous medium with a temporary fillercomposition that soaks in and fills the pores and then solidifies toform a barrier to penetration of the liquid masking composition; andtreating the porous medium with a temporary filler composition that isimmiscible with and denser than the liquid masking composition. Thesurface of the porous medium can be abraded after infiltrating the poreswith filler composition to expose uncoated and unfilled surfacesallowing direct adhesion of the mask to the support. The fillercomposition can be dissolved or otherwise removed from the porous mediumafter the liquid masking composition has been cured to a solid.

[0077] Examples of useful filler compositions include acetone-solublewaxes and lacquers, soluble waxes used for investment casting cores,water soluble salts, gels, Crystal Bond 509, soluble thermoplastics, andphase-change materials (e.g., ice, electrorheological fluids).

[0078] Referring to FIG. 3, one example of a method for rendering aporous medium temporarily nonporous using a filler composition includes:spinning a thin layer of a liquid-filler composition 132 onto arelatively flat surface 131 (e.g., a silicon wafer) (preferably thethickness of the filler composition layer is adjusted so as to fill thepores of the porous medium to a predetermined height); contacting afirst surface 136 of porous medium 130 to the spun-on filler composition132 (FIG. 3a), allowing filler composition 132 to seep into the pores ofthe porous medium to a predetermined depth (FIG. 3b); solidifying thefiller composition 132; and applying (e.g., by spinning on) a sufficientamount of liquid masking composition 134 to a second surface 138 of theporous medium 130 opposite the first surface through which fillercomposition 132 entered the porous medium 130. Liquid maskingcomposition 134 is applied so as to produce a layer of maskingcomposition of desired thickness on the surface of the porous medium.The remainder of the masking composition 134 can seep into the porousmedium (for purposes of adhesion) only to the surface of the solidifiedfiller 132. The method further includes curing the masking composition134; removing solidified filler 132; etching the negative features ofthe mask through the layer of porous medium 130 that is saturated withmasking composition 134 to at least a depth at which the solidifiedfiller 132 existed (FIG. 3d).

[0079] Other methods for preventing or limiting soak in includerestricting the volume of liquid masking composition that is applied tothe porous medium to only a fraction of the pore volume in the porousmedium causing the liquid to only partially fill the pores. One suchmethod includes spraying a liquid masking composition onto the porousmedium, while carefully controlling the flow rate and speed of the spraypattern. Another method involves spin coating the liquid maskingcomposition onto a non-absorbing sheet to obtain a uniform thin layer,and placing the porous medium in contact with the spun on liquid maskingcomposition. When the porous medium is peeled away from the sheet or thesheet is dissolved or melted, a thin coating of masking composition istransferred to the porous medium (i.e., the masking composition remainsadhered to the porous medium). The liquid masking composition can becured prior to or subsequent to removal of the sheet.

[0080] Another method for preventing soak in involves applying theliquid masking composition to a porous medium while the porous medium isspinning at high speed; the centrifugal forces spread the maskingcomposition into a thin layer before it has had time to soak inexcessively.

[0081] Another approach to preventing soak in involves forming a barrierlayer at or near the surface of the porous medium. After processing, thebarrier layer (and optionally, some of the porous medium) is removedfrom the negative features of the mask, so as to expose the porosity ofthe porous medium. Optionally, to improve adhesion of the mask to thesupport, the regions of the barrier layer that will correspond to thepositive features of the mask can be removed prior to application of themask. The barrier layer can be removed using various techniquesincluding, e.g., chemical etching, dry etching, ion milling, lasermachining, and melting (e.g., for thermoplastic based barriers). Thebarrier layer can also be formed by applying another material to thesurface of the porous substrate, e.g., laminating a film of a solidmaterial, such as dry film photoresist onto the porous medium; applyinga liquid barrier layer, preferably of high viscosity, using one of thetechniques discussed above that restrict soak-in volume; coating theporous medium with a thin layer of powder and melting the powder layerso as to form a non-porous coating; depositing a barrier film by vacuumevaporation, sputtering, CVD, or other process; and combinationsthereof.

[0082] In the case of a porous anode, soak in can be prevented using avariety of methods which include, applying a nonporous layer to thesurface of the porous anode and, after patterning the mask, removing thenonporous layer in the negative areas of the mask to expose the anode;sintering a partly-compacted powder in a mold, patterning the mask, andimmersing the structure in an etchant that attacks the metal of theanode, such that the outer non-porous layer of sintered anode materialis dissolved (in the unmasked regions); melting the surface of the anode(e.g., by flame, or contact with a hot surface); temporarily filling thesurface pores with a material, e.g., metal electrodeposited onto theporous surface; and by applying a nonporous barrier layer between themask and the anode.

Patterning and Fabricating the Electroplating Article

[0083] A variety of methods can be used to pattern the electroplatingarticle. Referring to FIG. 4, a method for forming an electroplatingarticle is shown. The method includes forming a micromold 140 by coating(e.g., by spinning) a layer of resist 142 (e.g., photoresistcommercially available under the trade designation SU-8 5 from MicroChemCorp.) onto a substrate 144 (e.g., a silicon wafer). Preferably thelayer of photoresist has a thickness a few microns greater than that thedesired thickness of the final mask. The photoresist can be patternedusing a photomask and, in the case of photopatternable resistcompositions, a light source (e.g., a UV light source). A positivefeature of the resist corresponds to a negative feature of the mask.Optionally, the micromold can be made from a non-stick material such as,e.g., polytetrafluoroethylene or polypropylene, and can include apattern formed, e.g., by reactive ion etching or excimer ablation, ormicromolded from a master mold according to processes similar toprocesses used in the fabrication of compact discs.

[0084] The micromold surface including the photoresist and the substratecan be passivated by allowing the micromold to be exposed to vapors of,e.g., (tridecafluoro-1,1,2,2-tetrahydrooctyl)-1-trichlorosilane(commercially available from United Chemical Technologies). A liquidmasking composition 146 is then poured over the raised pattern definedby the patterned photoresist. Support 148 is then pressed againstmicromold 140. Uniform pressure is applied such that liquid maskingcomposition 148 is forced out of the area 150 located between the raisedportions (i.e., positive features) of the resist pattern and the surfaceof support 148. Preferably, liquid masking composition 146 is completelysqueezed out of the areas 150 corresponding to the positive features ofresist 142. The entire assembly 152 remains in this mating relationshipuntil the liquid masking composition has cured. For a heat-curablemasking composition, the assembly can be transferred to an oven to cure.

[0085] After cure, excess mask material 154 surrounding support 148 isremoved. In the case of a mask that has been cured in the oven, theassembly is quickly disassembled to minimize differential thermalcontraction between support and the mold. The support and cured mask 156is pulled away from mold 140 such that cured mask 156 detaches frommicromold 140, yet remains adhered to support 148. Mask 156 exhibits apattern inverse to that of micromold 140. Micromold 140 can be reused.If necessary, micromold 140 can be cleaned to remove mask residue. Oneexample of a useful silicone cleaning composition is a siliconestripper, e.g., Amtex CCR (commercially available from Amtex ChemicalCorp.).

[0086] Any residual layer of masking composition remaining in negativefeatures 158 of mask 156 can be removed using dry etching (e.g., RIEwith a mixture of O₂ and CF₄ gas), which may also reduce the thicknessof the positive features of the mask. Uniform etching extending to theedge of the support can be accomplished by surrounding the support witha “dummy” substrate preferably of similar composition, such thatnon-uniformities due to edge effects are out of the area of interest.

[0087] When the mask is adhered to a porous medium, the etch may becontinued to remove any barrier layer present in the porous medium fromthe negative features of the mask and may be continued until a porousportion of the porous substrate is removed. If pores in a porous mediumhave been filled or are non-existent, the pores are re-established orestablished, e.g., by reactive ion etching.

[0088] Another method for forming an electroplating article is shown inFIG. 5. The method includes patterning a photoresist 142 onto a support148 (i.e., the porous medium or the prepared anode) to the approximatethickness desired for the final mask. The areas of support 148 occupiedby resist 142 correspond to negative features of the mask through whichmetal can be deposited. When patterning a porous medium that includes abarrier, the porous medium can be etched to remove the barrier layerfrom those areas of the porous medium that are not covered by resist.The method further includes applying a liquid masking composition 146 tosupport 148, and optionally vacuum degassing the masking composition. Aflat, smooth, non-stick (e.g., PTFE) sheet 160 is then pressed againstresist 142, and liquid masking composition 146 parallel to support 148,and pressure is applied to squeeze the liquid masking composition 146out from between resist 142 and sheet 160. Masking composition 146 isthen cured, sheet 160 is removed, and residual masking compositionoverlaying the resist is removed, e.g., by etching (e.g., reactiveionization etching using a mixture of O₂ and CF₄ gas). Resist 142 isthen removed to expose areas of the support previously occupied by theresist. When patterning a porous medium, mask material that has seepedinto the negative features of the mask from neighboring positivefeatures can be removed by etching both mask and porous medium to therequired depth. If pores of the porous medium have been filled or arenon-existent, the pores can be established or re-established.

[0089] Referring to FIG. 6, another method for forming an electroplatingarticle includes applying (e.g., by spinning on) a layer ofphotopatternable liquid masking composition 146, e.g., RMS-O33(commercially available from Gelest) in combination with aphotoinitiator (e.g., 2,2-dimethoxy-2-phenyl acetophenone (commerciallyavailable from Polysciences, Inc.)), to support 148. Liquid maskingcomposition 146 can be covered with a thin, oxygen-impermeable film(e.g., Mylar) to protect the composition from contact with oxygen.Masking composition 146 is then exposed to patterned light (e.g., UVlight transmitted through a photomask 162) to selectively cure the maskcomposition. The film is removed and the photopatternable maskingcomposition is developed (e.g., by dissolving with xylene) removinguncured masking composition 146. If a nonporous barrier layer exists, itis removed (e.g., by dry etching) from the negative features of mask156. Pores are established if necessary. For those photopatternablemasking compositions that are negative working the porous medium can becompletely saturated with masking composition until there is a surfacelayer of masking composition having the desired thickness. Afterphotopatterning,, the unexposed masking composition material (includingthat in the pores) is dissolved in the developer.

[0090] When patterning a porous medium, the porous medium can be tinteda dark shade or coated with an antireflection composition to reduce theamount of light scattered from the textured surface.

[0091] Referring to FIG. 7, another method for making an electroplatingarticle is shown. The method includes applying a liquid maskingcomposition 146 (or a solid mask) to support 148; curing liquid maskingcomposition to form a solidified mask 156; coating mask 156 with eithera thick resist 164 or a thin resist disposed on a thin metal layer (notshown); patterning resist 164 and, in the case of a metal layer, usingthe patterned resist to pattern the metal layer (e.g., by etching orlift-off); removing (e.g., wet etch, dry etch, or ion mill) mask 156using thick resist 164 (and metal layer if present) as a mask; and inthe case where the substrate is a porous medium, preferably removing thetop layer of the porous medium to open pores; and removing, e.g., bystripping, the remaining resist 164 (and metal layer if used).

[0092] Referring to FIG. 8, a method for forming an electroplatingarticle is shown which includes: applying a liquid masking composition146 (or a solid mask) to support 148 to the desired thickness; curing(if liquid) the masking composition to form solidified mask 156;exposing solid mask 156 to patterned ultraviolet light of intensity andwavelength suitable for ablating the mask and support material, e.g., aUV excimer laser beam; ablating mask 156 until support 148 is exposed;and, when patterning a porous medium, ablating barrier layer 170 (ifpresent) and, if necessary, the top layer of the porous medium to openpores.

[0093] Methods similar to methods used in relief printing can also beused to fabricate electroplating articles. One example of such a methodincludes: applying a liquid masking composition to a relief pattern,which might be produced by patterning a high aspect ratio photoresistsuch as AZ4620 or SU-8; pressing the relief pattern/masking compositionstructure against a support such that the masking composition adheres tothe support; and removing the relief pattern. The formed electroplatingarticle includes a support having a mask patterned with the inversepattern of the relief pattern.

[0094] Another example of such a method includes: creating a reliefpattern on the support by etching of the support, or applying a durablephotoresist, e.g., SU-8; coating a flat, smooth sheet with a thin,uniform layer of liquid masking composition; stamping the support/resistagainst the coated sheet (i.e., like a stamp and inkpad) to quickly mateand unmate the support/resist and the masking composition (preferablythe support and the sheet are kept parallel); and curing the liquidmasking composition.

[0095] Referring to FIG. 9, a method for forming an electroplatingarticle is shown in which a surface layer of porous medium 148 issaturated with a liquid masking composition to the thickness of thedesired mask. Liquid masking composition is solidified producing amatrix 174 of solid mask 156 and porous medium 148. Matrix 174 is thenpatterned, e.g., by etching or ablating selected areas of the matrix toa depth at least equal to the depth of the matrix “layer”, to formelectroplating article 176. Alternately, the method can includesaturating the entire porous medium with liquid masking composition,pattern curing the liquid masking composition, and removing the uncuredmasking composition.

[0096] Other methods of forming electroplating articles include, e.g.,applying masking composition selectively to a support by such processesas screen printing, stencil printing and inkjet printing; and for porousmediums, melting a surface layer of the porous medium and formingnegative features in the surface of the porous medium byetching/ablating through the melted layer to expose the pores of theporous medium and generate a relief pattern. The methods for formingelectroplating articles can also include etching the negative features(i.e., windows) of the mask pattern to increase the amount of relief onthe electroplating article. In the case of a porous medium and a printedsilicone mask, etching can be conducted by an oxygen plasma.

The Electroplating Method

[0097] In general, the invention features electroplating methods thatinclude contacting a substrate to be plated with an electroplatingarticle of the invention; selectively electroplating a first metal,e.g., a support or sacrificial metal; and electroplating a second metal,e.g., a structural metal. The step of electroplating a second metal caninclude selectively electroplating the second metal using anelectroplating article of the present invention or blanket depositingthe second metal. The electroplating method can be used to plate asingle layer of metal or the method can be repeated such that additionalmetal is plated onto previously plated metal layers producing amulti-layered structure. After a predetermined number of layer(s) havebeen plated, at least a portion of the support metal can be removed,e.g., by etching. The structural metal that remains defines amicroscopic or mesoscopic device.

[0098] The method can also employ two electroplating articles to plate asingle layer of one metal. Referring to FIG. 10, a first metal is platedin a first pattern 230, the same metal is then plated in second pattern232, to form plated metal layer 234. Second pattern 232 may overlapfirst pattern 230.

[0099] One example of an electroplating method of the invention is shownin FIG. 11. The method includes contacting a substrate to be plated 2with first article 4, which includes mask 6 and support 8, in thepresence of a first metal ion source (i.e., electrolyte and anode 10),depositing a first metal 12, e.g., a sacrificial metal,, contactingsubstrate 2 with a second article 14, which includes mask 16 and asupport 18, depositing a second metal 20, e.g., a structural metal, inthe presence of a second metal ion source (i.e., electrolyte and anode22), optionally planarizing the layer, and repeating this method usingdifferently patterned electroplating articles 4 a, 4 b, 14 a, 14 b toproduce multi-layered structure 24, which, after etching all ofsacrificial metal 12, becomes element 26. The second article can includea mask that has oversized positive features such that the surface areaof one or more positive features of the mask extends beyond thecorresponding surface area of the first plated metal.

[0100] The element formed during the electroplating method can remainattached to the substrate or can be removed from the substrate. Onemethod for removing the element includes plating a first layer ofsupport material onto the substrate such that etching removes the sourceof attachment of the element to the substrate.

[0101] Another electroplating method is depicted in FIG. 12. Theelectroplating method includes: contacting a substrate to be plated 2with an electroplating article (not shown); selectively depositing afirst metal 12 (i.e., either the structural or the support metal);blanket depositing a second metal 20 (FIG. 12a), and mechanicallyplanarizing the deposited layer to achieve a flat, smooth layer ofprecise thickness (FIG. 12b). The planarized surface can be rinsed toremove abrasive particles present on the surface. Preferably the supportmetal is selectively plated and the structural metal is blanketdeposited.

[0102] Examples of useful planarization methods include mechanical(e.g., diamond lapping and silicon carbide lapping),chemical-mechanical, and non-mechanical (e.g., electrical dischargemachining), planarization processes. Diamond lapping is a particularlypreferred planarization process. Diamond lapping can be performed usinga single grade of diamond abrasive, e.g., about 1-6 micron, or diamondabrasives of various grades. Lapping with different grades of abrasivecan be performed using separate lapping plates, or in different regionsof a single plate. For example, a coarse diamond abrasive can be appliedto the outer region of a spinning circular lapping plate, and a finediamond abrasive can be applied to the inner region. A removablecircular wall can be provided between the inner and outer regions toincrease segregation. The layer to be planarized first contacts theouter region of the plate, is optionally rinsed to remove coarseabrasive, and then is moved to the inner region of the plate. Theplanarized surface can then be rinsed using a solution, e.g.,water-based or electrolyte-based solution, to remove both abrasive andabraded particles from the planarized layer. The abrasive slurrypreferably is easily removable, e.g., water-soluble. Layer thickness,planarity and smoothness can be monitored, e.g., using an opticalencoder, wear resistant stops, and by mating the layer under a knownpressure with a precision flat metal plate and measuring the resistanceacross the plate-layer junction. Thickness of the plated metal can alsobe measured by contacting the plated metal with a mask having a patternthat is complementary to the plated metal pattern and measuring thedisplacement.

[0103] One example of a preferred planarization process includesallowing the work piece, i.e., the substrate having the layer to beplanarized, to rotate within a “conditioning ring” on the lapping plate.Lapping can also be performed by moving a workpiece around the surfaceof a lapping plate using the X/Y motion stages of the electroplatingapparatus without rotating or releasing the workpiece. In this way, thetangential motion of the plate with respect to the substrate rotatesthrough 360 degrees. The timing of slurry delivery may be synchronizedto the motion of the substrate such that the slurry is delivered to theplate. Movement of the workpiece can occur in paths other than circularincluding a path having a sinusoidal orbit of the form r=r₀+A sin Bθ.

[0104] The substrate to be plated can include a conductive surface or anonconductive surface provided with a conductive layer. The substrate tobe plated can be planar or nonplanar. The substrate to be plated canalso be a previously electroplated or deposited metal or a layer thatincludes at least one metal(s).

[0105] The electroplating method can be performed, e.g., on anintegrated circuit. One example of an electroplating method performed onan integrated circuit is shown in FIG. 13. To permit electrical contactduring plating, the aluminum pads can be connected to conductors thatterminate at distant contact pads, which can be temporarily tiedtogether by a bus. Referring to FIG. 13, electroplating method includes:spin coating a layer of polyimide 34 onto thin copper disk 36; adheringcopper disk 36 to bottom surface of silicon wafer 38, which includesaluminum pad 40, narrow conductor 42, contact pad 41, and passivationlayer 44; partially sawing through wafer 38 to assist separation of thedie after processing; spin coating photosensitive polyimide 35 on thetop surface of wafer 38 to protect aluminum pads 40 and 41 duringsubsequent etching and to fill saw line 46; patterning polyimide toexpose pads to be plated 40 and pads for electrical contact 41;degreasing wafer; immersing the structure in zincate plating solution;applying photoresist and patterning to create a bus; joining contactpads 41 by sputtering of copper to form a bus 48 that is in contact withpads 41 for the electroplating method; patterning resist over bus 48 toprevent nickel from depositing on bus 48; plating enough nickel 50 onaluminum pad 40 to allow planarization; removing the resist 35; makingelectrical contact with the plated metal; sputtering a planar base 51and plating a sufficient amount of copper 52 over the entire wafersurface to allow planarization; planarizing surface to expose nickel 50;electroplating the layers of the microstructure; etching copper 51 and52 including bus 48 and copper disk 36; and stripping polyimide 34thereby defining microstructure device 54 attached to wafer 38 (i.e.,the integrated circuit) (FIG. 13i).

[0106] The electroplating methods can employ cyclic plating to improveuniformity of the deposited metal layer. Cyclic plating includes verybriefly interrupting the current applied to the electrode insynchronization with removing the mask from the substrate to be plated,which simultaneously replenishes the electrolyte additives, vents anygases, and discharges particulates and broken-down additives from themicrovolume defined by the support, the substrate to be plated, and themask. Current is then re-applied in synchronization with contacting,i.e., remating, the mask with the substrate. This method can be repeateduntil the desired thickness of metal has been deposited. The walls ofthe mask can be given a slight taper or draft (i.e., negative featuresdefined by the mask are slightly larger on the side of the maskcontacting the substrate), to facilitate repeated contact of a mask witha substrate in the presence of a deposit of incomplete thickness.

[0107] Uniformity of the plated metal layer can be improved bycontrolling current density and adjusting current density on afeature-by-feature basis by controlling the local thickness, andoptionally the local porosity, of the support of the electroplatingarticle. Uniform plating can also be achieved by use as support aninsoluble anode having a thin layer of a soluble coating having athickness calculated to provide the desired thickness of plated metal onthe substrate. Once the finite amount of ions in the volume ofelectrolyte within the area defined by the mask, the coating and thesubstrate are plated, plating ceases. As long as the coating is uniformin thickness, the plated metal will be uniform in thickness.

[0108] Hydrogen bubble formation can also be minimized by employing alow current density to increase current efficiency; decreasingtemperature and/or pressurizing the electrolyte in bulk to increase thesolubility of hydrogen in the electrolyte; employing a mask materialthat is impermeable to the electrolyte but gas permeable (e.g., ahydrophobic microporous material); performing the electroplating methodunder vacuum so that gas bubbles are pulled out of the mask features;employing antipitting agents (e.g., SNAP for nickel sulfamateelectrolytes) to minimize the formation of pits by reducing theattachment of the gas bubbles to the substrate; increasing the maskingpressure, which can locally increase electrolyte pressure due to reducedmicrovolume, which will establish large pressures on the electrolyte inlocalized areas keeping hydrogen in solution; and incorporating hydrogengettering agent into the mask material (e.g., by mixing a fine powderinto the liquid masking composition)

[0109] Examples of useful etching compositions for selectively strippingcopper from nickel structures include: solutions of ammonium hydroxideand copper sulfate, solutions of ammonium hydroxide and sodium chlorite,with ammonium hydroxide-copper sulfate solution being preferred foretching structures attached to CMOS devices, and Enstripe C38commercially available from Enthone OMI. Etching can also be performedin the presence of vibrations, e.g., ultrasound applied to theelectrolyte or the substrate being plated, pressurized jets of etchantcontacting the metal to be etched, and surfactant. Flash present on thestructural metal, e.g., in the form of thin projections extending fromthe surface of the structural metal, can be removed, e.g., by acidetching or electropolishing.

[0110] The electroplating methodes can be used to manufacture elementshaving complex microstructure and close tolerances between parts. Oneexample of a method for manufacturing elements having parts that fitwith close tolerances, e.g., caps between the parts are between about1-5 um, involves electroplating the parts of the device in anunassembled, preferably pre-aligned, state. Once manufactured, theindividual parts can be moved into operational relation with each other.Referring to FIG. 14, a method of manufacturing device 188 includinggear 190 and shaft 192 having retaining clips 200 includes theelectroplating methods disclosed above. Assembly fixture 194 is platedin a pre-aligned location with gear 190. Chuck 196 (e.g.,electromagnetic or vacuum) secures the assembly fixture pieces 194 assupport material 198 is etched. During etching gear 190 may fall intocontact with shaft 192. Chuck 196 is then lowered, causing assemblyfixture 194 to press gear 190 over retaining clips 200 on shaft 192 andinto final position, as shown in FIG. 14c. Chuck 196 is then raisedremoving assembly fixture 194 from the completed device 188, as shown inFIGS. 14d-e.

[0111] The electroplating method can also be used to manufactureelements in which at least a portion of the support metal is enclosedwithin the structural material such that the enclosed structural metalis not etched away during the removal process. Referring to FIG. 15, across section of a plated element 236 is shown in which support metal238 remains encapsulated within structural metal 240 after support metal238, that is accessible by etchant, is removed.

[0112] The electroplating processes can also be used to manufacturetooling for molding (e.g., injection molding, metal injection molding,reaction injection molding, thermoforming, blow molding, and diecasting). Mold inserts can be manufactured by orienting the two moldinserts so that the ejection axis of the part is parallel to thestacking axis of the layers and the parting surface of the part to bemolded is the last layer deposited. The electroplating methods can beused to form parts that include undercuts as shown in FIG. 16a, to formparts without draft as shown in FIG. 16b, and to form molds withoutundercuts and with draft by depositing layers of structural materialwhere each subsequently plated layer of structural metal lies entirelywithin the boundary of the previously deposited layer (e.g., layers801-805) of structural metal, as shown in FIGS. 16c and d, optionallywithout the use of support material. Referring to FIG. 16c, layer 800 isdeposited before layer 801, and so on.

Electroplating Apparatus

[0113] The electroplating method can be performed in a variety ofelectroplating apparatus. One particularly useful apparatus for carryingout an electroplating method is shown in FIG. 17. Apparatus 56 includestwo baths 58, 60 (e.g., a nickel plating bath and a copper platingbath), and an inspection station 62. Each bath 58, 60 is constructed tobe capable of electroplating a different metal. Each bath 58, 60includes an electrolyte, an anode 59, 61, and an electroplating article4, 14. As shown, apparatus 56 accommodates a single substrate to beplated 2. The apparatus can be constructed to accommodate multiplesubstrates to be plated and multiple electroplating articles. Eacharticle 4, 14 includes at least one patterned conformable mask 6,16 andis capable of depositing a pattern of metal.

[0114] The mechanical and electrochemical control of the electroplatingmethod can be controlled by computers. Substrate to be plated 2 istransported by precision motion stages 64 x, 64 y, 64 z, equipped withDC servo motors, stepper motors or combinations thereof, and precisionencoders, between plating baths 58, 60 and rinsing station 66. Substrate2 suspended on chuck 68 enters first bath 58, positions itself over mask6, contacts mask 6, and undergoes plating. After a predeterminedthickness of metal has been plated onto substrate 2, substrate 2 isremoved from bath 58, rinsed and transferred to second plating bath 60where it contacts a second mask 16, undergoes plating to a predeterminedthickness (preferably the same thickness of the first deposited metal),is rinsed, and is returned to first bath 58. Inspection station 62,including a high-resolution video microscope system with PC framegrabber, can be used in conjunction with control software toautomatically record images of the deposited layers to a hard disk.Preferably apparatus 56 is enclosed in a sealed chamber and equippedwith a vacuum system to degas the mask.

[0115] Useful mechanisms for applying controlled, uniform pressure tothe substrate include applying a fluid pressure (e.g., through apneumatic or hydraulic cylinder). One particularly preferred method forapplying uniform pressure across a circular substrate includes applyingpressure at the center of the substrate through a ball joint (e.g., aball sandwiched between the cylinder or extension thereof and thesubstrate, possibly retained by a countersink in each). The ball allowsthe substrate to tilt as needed to conform to the mask surface and tofind an equilibrium position within which pressure is uniformlydistributed. The substrate can be held against the ball by surroundingthe substrate with a tight-fitting flexible tube that is anchored at oneend to the moving member.

[0116] A very stiff, precision mechanical slide (e.g., a mechanicalslide that incorporates crossed roller bearings) can be used to providerepeatable positioning of the mated substrate. The stages that move inthe plane of the deposited layer, X/Y stages, can be fixed in locationby clamps (e.g., an electromagnetic brake).

[0117] The device (e.g., the chuck) that carries the substrate to beplated can include a sliding insulating tube that moves into position asmetal layers are added to the substrate. Referring to FIGS. 17 and 18,sliding insulating tube 67 is shown in cross section in contact withedge mask 244 on support 14 and surrounding substrate 2 and plated metallayers 250.

[0118] The electroplating apparatus can be modified to include a devicecapable of directing a spray of electrolyte into the volume defined bythe negative features of the article just prior to contacting thearticle to the substrate to be plated.

[0119] The electroplating apparatus can include a filtration system tocontrol particulate contamination within the apparatus. After theelectroplating articles and substrate(s) are loaded into theelectroplating apparatus, the apparatus can execute a self-cleaningcycle that includes pressurized rising, ultrasonic agitation, andfiltration. The air within the apparatus can be cleaned by a filtrationsystem, e.g., a HEPA filtration system. The air and electrolytefiltration processes can operate continuously throughout theelectroplating method. The electrolyte filtration system can beincorporated into a heating and pumping system to continuously circulateand warm the electrolyte to maintain homogeneous concentration andconstant temperature.

[0120] The thickness of the plated metal and plated metal layer can becontrolled, e.g., by measuring the deposition rates of the metals andplating for a predetermined period; monitoring the integrated current,with adjustments for plating efficiency, normalizing for calculated maskarea and calculating plating thickness; and through closed loopthickness control. The closed loop system includes inputing an estimate,based upon measured metal plating rates, into the software that controlsthe eletroplating method; plating a first metal to less than the desiredthickness, pressing the substrate against a second electroplatingarticle, such that the mask of the electroplating article contacts thefirst plated metal; forcing the substrate to move away from the supportby an amount equal to the thickness of the plated layer; reading thethickness of the first plated metal using a high resolution (e.g., 0.1um) encoder, linked to the substrate chuck; inputing this data into thesoftware to update the stored rate value for the first metal; platingthe remaining thickness of the first metal layer. This process and itscomplement for measuring the plating thickness of the second platedmetal can be repeated every few layers as a calibration.

[0121] The position and orientation of the mask of the electroplatingarticle with respect to the substrate and motion axes of theelectroplating apparatus (described below) can be determined by analignment procedure that uses reserved areas on the substrate to beplated and at least two distantly separated masks, each bearing analignment pattern. To align the mask to the substrate, a thin layer ofmetal is plated onto the alignment pattern of the substrate, therotational and translational misalignment of the mask with respect tothe substrate is measured, e.g., using a video microscope, andcorrections. Alignment accuracy can be verified by stripping the platedpatterns and re-plating new patterns. Alignment can be repeatedthroughout the electroplating method as necessary.

[0122] Another example of a useful alignment method employs a vernierpattern in which a pattern of fine lines having a first pitch isdeposited over a second pattern of lines having a different pitch. Thepitch spacing of the deposited pattern compared to the existing patternprovides an indication of the alignment error.

[0123] Referring to FIG. 19, a portion of another electroplatingapparatus 66 that includes bath 68 containing ions of a first metal,e.g., a nickel plating bath, bath 70 containing ions of a second metal,e.g., a copper plating bath, and multiple electroplating articles 72 a-fand 74 a-f, is shown. Each substrate to be plated 2 (labeled 2 a-e)enters apparatus 66 at the left end 76 of bath 68 contacts article 74 a,becomes plated with first metal in the pattern of the mask of article 74a, transfers to bath 70 after rinse (not shown), contacts article 70 a,becomes plated with a second metal in the pattern of the mask on article70 a, transfers to article 74 b after rinse (not shown), in bath 68 andso on. As depicted, substrate 2 a has received deposits of the firstmetal and the second metal for the first three layers of themicrostructure and the first metal portion of the fourth layer.Substrate 2 b is one layer behind substrate 2 a, substrate 2 c is twolayers behind wafer 2 a, etc.

[0124] For elements (e.g., devices) that require dozens or hundreds ofdeposited layers. the electroplating system can be arranged in anannular design in which the electroplating articles are arranged inrings and in which the individual electroplating articles are replacedafter having contacted each of the substrates to be plated. One exampleof an apparatus for mass producing electroplated structures is shown inFIG. 20. Apparatus 78 is designed to process 24 eight-inch diametersubstrates 2. Apparatus 78 is concentric in design and includes twoouter rings 80, 82 and a central disk 84. Outer ring 80 includeselectrolyte bath 84 and electroplating articles (not shown) forselectively plating a first metal. Inner ring 82 includes an electrolytebath 86 for blanket-plating a second metal. Inner ring 82 can includeelectroplating articles for selectively plating the second metal.Rotating lapping plate 85 (if required), for planarizing the platedmetal layers, is located at the center of apparatus 78. All processes(selective plating, blanket or selective plating and, optionally,planarization) occur during a single cycle, but on different substrates2. At the end of the cycle, the substrates undergoing plating move inthe pattern shown, in part, by arrows. Eight layers have been depositedafter having completed all of the cycles in the system and arriving backat the starting point. Prior to the first substrate arriving back at thefirst plating article, the first plating article can be replaced by anew plating article. Likewise after the other plating articles havecontacted each of the substrates they can be replaced, and substrates 2can continue around apparatus 78, receiving as many layers as arerequired for the device being made. Rinsing stations are not shown butcan be located in the spaces between the plating articles. Such anapparatus would permit the simultaneous manufacture about 2.5 milliondevices, each 500 microns square by 200 microns tall, in a 8 hourperiod.

[0125] The electroplating apparatus can also include a single bathcontaining ions of at least two metals (e.g., a Watts bath with addedcopper sulphate). A method for selectively depositing two metals from acommon plating bath of their ions is described in H. Yahalom and O.Zadok, “Formation of Compositionally Modulated Alloys byElectrodeposition,” J. Material Sci., Vol. 22, p. 494 (1987). Theplating bath includes at least two electroplating articles, each ofwhich is dedicated to plating one of the metals. The articles caninclude a single mask pattern or multiple mask patterns in a side byside arrangement on the surface of the support. In the case of anarticle having multiple mask patterns, the substrate can contact thedifferent mask patterns in a predetermined sequence, alternating withthe mask pattern(s) on the second article, to build a three dimensionalstructure. Referring to FIG. 21, an electroplating apparatus 88 thatincludes a single bath 90 containing ions of two metals, e.g., nickeland copper ions, articles for plating the first metal 92, articles forplating the second metal 94, and substrates 2 a-e, is shown.

[0126] Each substrate 2 enters apparatus 88 at the left end 96 of bath90, contacts electroplating article 92 a becomes plated with the firstmetal in the pattern of the mask of electroplating article 92 a,transfers to and contacts article 94 a, becomes plated with the secondmetal in the pattern of the mask on electroplating article 94 a,transfers to electroplating article 92 b, and so on. As depicted,substrate 2 a has received deposits of the first metal and the secondmetal for the first three layers of the microstructure and the firstmetal portion of the fourth layer. Substrate 2 b is one layer behindsubstrate 2 a, substrate 2 c is two layers behind substrate 2 a, and soon.

[0127] A variety of methods can be used to improve the copper depositionrate in a common bath electroplating system including, e.g., pulsing theplating current, increasing temperature (e.g., laser enhanced plating),pumping electrolyte through the support of the electroplating article,ultrasonic vibration, and increasing the copper content in the vicinityof the copper disk. One method for locally increasing the concentrationof copper includes galvanostatic dissolution of the copper anode whileplating onto a dummy substrate. By applying a current pulse at a densityof, e.g., about 20-50 mA/cm², both nickel and copper are deposited ontothe dummy substrate until sufficient copper to form a layer (about 1-2um thick) is generated in the electrolyte located between the anode andthe substrate. At this point the dummy substrate is substituted with thereal substrate and the anode is replaced with a nickel anode. Copper isthen deposited potentionstatically.

[0128] Another method for locally increasing the concentration of copperincludes employing a electroplating article holder 98 as shown in FIG.22. The volume of electroplating article holder 98 contains copper richelectrolyte and is defined by side walls 100 of a cylinder, a poroussupport 102 having a conformable mask 104, and anode 106 (e.g., aninsoluble platinized titanium anode). Electroplating article holder 98includes inlet and outlet ports for transferring electrolyte. Thiselectroplating article holder can be immersed within a nickel platingbath, optionally separated by a barrier through which the substrate canintermittently pass.

[0129] In general when there is a risk of spontaneous deposition onto asubstrate while not in contact with an electroplating article, thesubstrate preferably is biased at a more positive potential than that atwhich copper reduction would occur until the substrate has contacted thecopper electroplating article and current has been applied. Similarly,when current is removed, the substrate preferably is again biased untilthe substrate is removed from the electrolyte, or applied to anotherarticle and current is again applied.

[0130] Another electroplating apparatus is shown in FIG. 23. Apparatus260 includes baths 262, 264 (e.g., a nickel plating bath and a copperplating bath), by an inspection station 266, and lapping station 268.Each bath 262, 264 is constructed to be capable of electroplating adifferent metal. Each bath 262, 264 includes an electrolyte and an anode270, 272. Bath 264 also includes an electroplating article 274 forselectively depositing a first metal. Bath 262 is used for blanketdepositing a second metal. Bath 262 includes a mask 276 for insulatingthe sides of element being fabricated on substrate 2 to prevent metalfrom plating on the sides of either one. Referring to FIG. 24, a portionof electroplating apparatus 260 in which substrate 2 is positionedwithin electroplating bath 262 and is insulated, in part, by mask 276 isshown. Substrate 2 includes a selectively deposited layer 278 and ablanket deposited layer 280.

[0131] Referring to FIG. 25, an example of an electroplating apparatusthat includes an electroplating article that includes a porous membraneis shown. Electroplating article 108, which is in contact with substrateto be plated 2, includes a relatively more rigid porous medium 110having a relatively more coarse porosity, and relatively more thin,flexible porous membrane 112 having a relatively more fine porosity, andpatterned mask 114 adhered to membrane 112. Patterned mask 114 is incontact with substrate 2 and anode 116 is disposed beyond porous medium110. A metal deposit 118 is formed in the opening (i.e., a negativefeature) defined by mask 114.

[0132] Referring to FIG. 26, another example of an electroplatingapparatus 120 that employs a porous membrane 112 is shown. Porousmembrane 112 is mounted on drumhead 122 in a way that allows for handingand processing, maintains position of membrane 112 with respect to thesubstrate, and allows pressure to be exerted on porous membrane 112through rigid porous medium 110 contacting porous membrane 112. Porousmembrane 112 is clamped between concentric O-rings 124, and pulled tautover a rigid porous medium, or, as shown, a cylindrical, hollow “barrel”126 by tightening screws 128. If a barrel is used, rigid porous medium110 is placed within barrel 126 so as to make contact with one side ofmembrane 112. Plating substrate 2 contacts the other side of porousmembrane 112. An intermediate compliant material (not shown) e.g., anopen pore foam, may be disposed between porous membrane 112 and rigidporous medium 110 to provide a more uniform contact pressure between themask and plating substrate 2.

Automated Processing

[0133] The invention also features a method for generating a maskpatterns of very thin cross section for a three dimensional structureand a method for automated electroplating that includes contactingelectroplating articles having the generated mask patterns in apredetermined sequence to form the three dimensional structure.

[0134] The method employs an automatic mask minimization algorithm foroptimizing the number of masks for a given geometry. Application of themethod to a valve like device 602, shown in FIG. 27, can be describedwith reference to perforated lines A-D which indicate cross sections ofthe device 602. Cross sections B and C are identical and cross sectionsA and D are identical. A single mask can be used for cross sections Band C and another mask can be used for cross sections A and D. Thealgorithm compares the newly calculated cross sections with thepreviously calculated cross section for the same device or possiblythose used to make the other devices and same metal. A new mask isgenerated if the difference between the two cross sections exceeds somepredetermined (e.g., user specified) tolerance. This allows the numberof masks to be minimized, allowing a greater number of layers to beproduced from fewer electroplating articles. The program also generatesan apparatus control file which directs the software that controls theelectroplating apparatus such that masks are selected in a predeterminedsequence corresponding to mask location within the electroplatingapparatus and the layer being plated. The system can also export alayout file representing the first cross section of the part to befabricated, allowing pad design for CMOS interfacing using a standardlayout editor. The system can also display calculated cross sections tothe user to allow error checking.

[0135]FIG. 28 is a functional block diagram of an exemplary computingsystem for calculation of cross sections of a three dimensionalstructure in accordance with an embodiment of the present invention. Asshown in FIG. 28, system 610 may include a processor 612, a memory 614(e.g., a random access memory (RAM), and a program memory (for example,a writable read-only memory (ROM) such as a flash ROM)), input devices616, and output devices 618. Processor 612 includes a central processingunit (CPU) that forms part of a general purpose computer, such as a PC,Macintosh, or workstation. Memory 614 stores program code for executionby processor 612 including operating system code and application programcode, and generally represents a magnetic hard drive or other storagedevice in combination with a random access memory accessed by processor612. As one example, memory 614 could be realized in part by a storagedrive contacting removable storage media carrying the applicationprogram code. Input devices 616 include input media for entry of userinput, such as a keyboard, mouse, and the like. Output devices 618include display devices including a view screen that provides graphicoutput, e.g., a CRT or flat panel monitor, a printer (e.g., a desk topprinter, an inkjet printer, a laser printer, a photoplotter, and thelike), the electroplating apparatus of the present invention, alinotronic printer and the like.

[0136]FIG. 29 is a flow diagram illustrating a method for generatingmask geometries and machine control parameters for fabrication of athree dimensional structure. When the user starts the applicationprogram, as indicated by reference numeral 620, processor 612 receivesand processes input corresponding to the three dimensional geometry of astructure to be cross sectioned from input devices 616 as indicated byblock 622. Processor 612 determines the extents in layer plane of theentire geometry of the three dimensional structure as indicated by block623. Processor 612 sets M, the number of layers (including one or morecross sections), equal to 1 and generates cross sections for the Mthlayer, as indicated by block 624. Processor 612 reads inputs relevant toeach mask geometry including, e.g., scaling of the three dimensionalgeometry, layer thickness, mask dimensions, number of copies andspacing, and tolerance for mask minimization, as indicated by block 625.Processor 612 creates the geometry of mask corresponding to the Mthlayer, as indicated by block 616, writes the geometry of the crosssection to a mask pattern file, indicated by blocks 628 and 630, andwrites mask identification numbers for the Mth layer to a machinecontrol file, as indicated by blocks 628 and 632. Memory 614 stores maskpattern in the mask pattern file, as indicated at block 630. Memory 614stores location information in machine control file, as indicated atblock 632. Processor 612 queries if additional cross sections are neededto complete the geometry of the three dimensional structure, asindicated at block 634.

[0137] If so, processor 612 increments M by 1 and generates a crosssection for Mth layer as indicated at block 636. Processor 612 creates ageometry of masks for Mth layer and sets N to zero, as indicated byblocks 638 and 640. Processor 612 queries whether the geometry of themask for the Mth layer is the same as or similar within a predeterminedtolerance value to that of masks for the M-Nth layer, as indicated atblocks 642 and 646.

[0138] If so, processor 612 replaces the mask geometry of the Mth layerwith that of the M-Nth layer as indicated at block 648. Processor 612writes a mask identification number for the layer M to the machinecontrol file (as indicated by blocks 650 and 652) and writes the maskgeometry to the mask pattern file.

[0139] If not, processor 612 queries whether M-N is greater than orequal to 1 as indicated at block 654.

[0140] If so, processor 612 increments N by 1 and compares the geometryof mask for Mth layer with that of mask for M-Nth layer, as indicated atblock 642. If processor 612 calculates that the geometry of the Mthlayer has been compared to the geometry of each previous mask and nogeometry matches, then processor 612 creates a geometry of the mask forthe Mth layer, as indicated at block 656. Processor 612 then writes thegeometry for the Mth layer to the mask pattern file (as indicated byblock 658), sends an output to mask pattern file, as indicated by block660, and writes mask identification number for the Mth layer to themachine control file (as indicated by blocks 650 and 652).

[0141] Processor 612 queries whether additional cross sections arerequired to be made of the three dimensional object (as indicated byblock 634).

[0142] If so, processor 612 increments M by 1 and continues the processagain.

[0143] If not, the process ends.

[0144]FIG. 30 is a flow diagram illustrating a method for electroplatinga metal onto a substrate using patterned masks that represent a crosssection slice of a three dimensional object. When the user starts theapplication program, as indicated by reference numeral 720, processor612 signals to the electroplating apparatus to perform machineinitialization and sets M, the number of the layers plated equal tozero, as indicated at block 722. Processor 612 increments M by 1 (asindicated by block 724), sets P (i.e., the number of different metals tobe plated) equal to 1 and optionally biases the substrate to preventspontaneous deposition of the metal (as indicated by block 726).Processor 612 reads machine control file (indicated by block 730 todetermine which layer is to be plated, and reads mask location file(indicated by block 732) to calculate the location of the mask patternto be plated (indicated by block 728). Processor 612 directs theelectroplating apparatus to align the substrate to be plated with themask for material P of layer M and to contact the substrate to the mask.Processor 612 optionally measures layer thickness, if necessary, asindicated by block 734. Processor 612 receives input that the substrateis in contact with the mask and turns off substrate bias (if turned on),as indicated by block 736. Processor 612 instructs apparatus to depositmaterial P for layer M, as indicated by block 738. Processor 612receives input that layer has been deposited and applies a bias to thesubstrate, if required, as indicated at block 740. Processor 612instructs apparatus to remove the substrate from contact with the mask(as indicated at block 740), and to planarize layer M to predeterminedthickness (if necessary), as indicated at block 744. Processor querieswhether P is greater than the number of metals of layer M, as indicatedby block 746.

[0145] If so, processor 612 increments P by 1 (as indicated by block748), and drives the electroplating apparatus to align the substratewith a mask for P (i.e., Pi+1) metal of layer M, as indicated by block728. Processor 612 drives electroplating apparatus to contact thesubstrate with the mask, and the above process is repeated until P isequal to the number of metals on layer M.

[0146] If not, processor 612 queries whether M is the final layer (asindicated by block 750).

[0147] If so, processor 612 ends the electroplating process as indicatedby numeral 752.

[0148] If not, processor 612 increments M by 1 as indicated by block724, and processor 612 drives the electroplating process until the finallayer has been plated.

[0149] The data process and control processes of the invention can beimplemented in digital electronic circuitry, or in computer hardware,firmware, software, or in combinations thereof. The data process andcontrol process of the invention can be implemented in a computerprogram product tangibly embodied in a machine-readable storage devicefor execution by a programmable processor; and method steps of theinvention can be performed by a programmable processor executing aprogram of instructions to perform functions of the invention byoperating on input data and generating output. The data processes andcontrol processes of the invention can advantageously be implemented inone or more computer programs that are executable on a programmablesystem including at least one programmable processor coupled to receivedata and instructions from, and to transmit data and instructions to, adata storage system, at least one input device, and at least one outputdevice. Each computer program can be implemented in a high-levelprocedural or object-oriented programming language, or in assembly ormachine language if desired; and in any case, the language can be acompiled or interpreted language. Suitable processors include, by way ofexample, both general and special purpose microprocessors. Generally, aprocessor will receive instructions and data from a read-only memoryand/or a random access memory. Storage devices suitable for tangiblyembodying computer program instructions and data include all forms ofnon-volatile memory, including by way of example semiconductor memorydevices, such as EPROM, EEPROM, and flash memory devices; magnetic diskssuch as internal hard disks and removable disks; magneto-optical disks;and CD-ROM disks. Any of the foregoing can be supplemented by, orincorporated in, ASICs (application-specific integrated circuits).

[0150] To provide for interaction with a user, the data process andcontrol processes of the invention can be implemented on a computersystem having a display device such as a monitor or LCD screen fordisplaying information to the user and a keyboard and a pointing devicesuch as a mouse or a trackball by which the user can provide input tothe computer system. The computer system can be programmed to provide agraphical user interface through which computer programs interact withusers.

[0151] Other embodiments are within the claims. Although the abovedescription is directed to planar substrates, the substrate could benon-planar. In such embodiments, the electroplating article can besufficiently flexible to conform to the shape of the substrate surface,or shaped to match the surface. For example, the electroplating articlecould be wrapped around a cylindrical substrate. Masking pressure can beapplied to nonplanar substrates through a powdered medium that conformsto the mask.

[0152] In addition, although the electroplating methodes have beendescribed above with respect to two metals, a variety of materials,e.g., polymers, ceramics and semiconductor materials, and any number ofmetals can be deposited either by the electroplating methodes describedabove, or in separate processes that occur throughout the electroplatingmethod. A thin plating base can be deposited, e.g., by sputtering, overa deposit that is insufficiently conductive (e.g., an insulating layer)so as to enable continued electroplating. Multiple support materials canbe included in the electroplated element allowing selective removal ofthe support materials.

[0153] The electroplating methods of the invention can be used incombination with other processes. Referring to FIG. 31, for example,electromagnetic motor 178 including armature windings 180 connected toan integrated circuit at aluminum pads on substrate 182, can be formedby interrupting the electroplating method and etching a portion of thesupport metal (e.g., using a patterned resist) to produce cavity 184(i.e., the rotor core of the motor) defined by structural metal 186serving as an etch stop. Cavity 184 is then filled with a magneticpowder (e.g., Ne-Fe-B), which is subsequently sintered and magnetized.If necessary, metal is sputtered onto the sintered magnetic powder toestablish a plating base and the electroplating method can be resumed.Such cavities can be filled with solids, fluids or evacuated to form avacuum.

[0154] Where multiple metals are to be deposited, the metals can beselectively deposited on the substrate by masking only the substrate.The metal being selectively plated onto the substrate is also depositedonto the previously deposited metals. After each of the metals for agiven layer has been deposited, or more frequently, the layer isplanarized to the desired thickness. Alternatively, the mask can coverall of the previously deposited metals. The mask can also be stepped inthickness to accommodate the topography of a partially plated substrate.

[0155] Another embodiment of the electroplating method involvesmanufacturing a structure well defined in shape and position accordingto the following method: preparing a piece of rigid, high strengthmaterial with an interconnected porosity (e.g., partly-sinteredceramic); shaping one surface of this piece such that it has the inverse(in the mold making sense) shape to that of the desired deposit;positioning the piece so that its surface lies opposite the substrate tobe plated, at the desired position of the final deposit surface, andplace an anode on the other side of it; plating metal onto the substratewhile moving the piece (continuously or periodically) with sufficientforce and in such a way that its surface still remains matched to thatof the desired deposit (for a planar surface, move it within the plane,for a cylindrical surface, move it axially, etc.) (The movement can be avibration sufficiently large to shear and remove any portion of thedeposit that extends into the pores of the piece); continuing platinguntil the entire volume between the substrate and the piece is filledwith the deposit, at which point the deposit will have molded itself tothe shape of the piece. The piece can be disposed of, or periodicallyreconditioned by chemically flushing the piece with fluid, dissolvingthe clogging material or placing the clogged surface in contact with ananode and deplating it onto a substrate in an electrolyte.

[0156] Referring to FIG. 32, another embodiment of an electroplatingarticle is shown. Electroplating article 200 includes a mask adhered toand coextensive with a patterned, rigid substrate (e.g.,polymethylmethacrylate). During the electroplating method a deposit isformed in the window(s) (i.e., negative mask features) of the article.More specifically, substrate 204 is contacted with a first patternedelectroplating article 200, as shown in FIG. 32a; a first metal deposit206 is formed in a shape defined by the pattern 202 in firstelectroplating article 200, first article 200 is then removed (FIG.32b); substrate 204 is then contacted in alignment with a secondpatterned electroplating article 208 (FIG. 32c), deposit 210 is formed,and second article 208 is removed (FIG. 32d). The plated metal is thenplanarized and the method repeated until an element of sufficientthickness and dimension has been achieved. The electroplating articlescan include a region 210 of overlapping plated metal, which will have acorresponding greater thickness. The overlapping region can beplanarized to create a planar layer of deposited metal. Masking pressurecan be applied by pressing an anode or porous medium against theelectroplating article. The mask can be made stiffer by increasing itsthickness.

[0157] Although the electroplating methodes have been described withrespect to contacting a cathode with an article and plating onto acathode, it is contemplated that the electroplating article can beplaced in contact with a substrate functioning as an anode such thatmetal is selectively removed from the anode in a pattern correspondingto the pattern on the electroplating article. Such a process can beemployed to selectively etch, engrave, and polish a substrate, e.g., aplaque.

What is claimed is:
 1. An electrodepositing article comprising: a) asubstrate having a first major surface; and b) a conformable maskdisposed in a pattern on said first major surface of said substrate,said article being capable of electroplating a pattern of metalcomplementary to said pattern of said conformable mask onto an electrodewhen said article is placed in contact with the electrode in thepresence of a metal ion source and subjected to an electric field.
 2. Amethod for manufacturing an electroplating article, said methodcomprising: a) applying a conformable mask to an article comprising afirst substrate and a patterned resist disposed on said first substrate;b) contacting a second substrate to said conformable mask such that saidconformable mask obtains a pattern complementary to said pattern of saidresist; c) separating said first substrate from said conformable mask,said conformable mask remaining adhered to said article; and d) removingsaid resist, said article being capable of electroplating a pattern ofmetal corresponding to the complement of said pattern of saidconformable mask onto an electrode when said article is placed incontact with the electrode in the presence of an electrolyte solutionand subjected to an electric field.
 3. A method for manufacturing anelectrodepositing article, said method comprising: a) providing a porousmedium having a first surface; b) treating said porous medium to createone or more nonporous regions; c) applying a film to said first surfaceof said porous medium; d) patterning said film to create a patternedmask; and e) removing at least a portion of said one or more nonporousregions, said article being capable of electroplating a pattern of metalcorresponding to the complement of said pattern of said conformable maskonto an electrode when said article is placed in contact with theelectrode in the presence of an electrolyte solution and subjected to anelectric field.